Back to the main page of this manual  Input reference of CP2K version 8.1 
CP2K_INPUT /
FORCE_EVAL /
DFT /
XC /
WF_CORRELATION /
RI_RPA /
GW
&GW {Logical} 

Activates cubicscaling RPA, GW and LaplaceSOSMP2 calculations.  
This keyword cannot be repeated and it expects precisely one logical.  
The lone keyword behaves as a switch to
.TRUE. 

Default value:
.FALSE. 
ANALYTIC_CONTINUATION {Keyword} 

Defines which type of analytic continuation for the self energy is used  
This keyword cannot be repeated and it expects precisely one keyword.  
Default value:
PADE 

List of valid keywords:

BSE {Logical} 

If true, electronic excitation energies are computed from the BetheSalpeter equation on top of GW eigenvalues. Parameter of BSE can be adjusted in the corresponding section.  
This keyword cannot be repeated and it expects precisely one logical.  
The lone keyword behaves as a switch to
.TRUE. 

Default value:
.FALSE. 
CORR_MOS_OCC {Integer} 

Number of occupied MOs whose energies are corrected by RIG0W0. Counting beginning from HOMO, e.g. 3 corrected occ. MOs correspond to correction of HOMO, HOMO1 and HOMO2. Numerical effort and storage of RIG0W0 increase linearly with this number. In case you want to correct all occ. MOs, insert a number larger than the number of occ. MOs.  
This keyword cannot be repeated and it expects precisely one integer.  
Default value:
10 

Alias names for this keyword: CORR_OCC 
CORR_MOS_VIRT {Integer} 

Number of virtual MOs whose energies are corrected by RIG0W0. Counting beginning from LUMO, e.g. 3 corrected occ. MOs correspond to correction of LUMO, LUMO+1 and LUMO+2. Numerical effort and storage of RIG0W0 increase linearly with this number. In case you want to correct all virt. MOs, insert a number larger than the number of virt. MOs.  
This keyword cannot be repeated and it expects precisely one integer.  
Default value:
10 

Alias names for this keyword: CORR_VIRT 
CROSSING_SEARCH {Keyword} 

Determines, how the self_energy is evaluated on the real axis.  
This keyword cannot be repeated and it expects precisely one keyword.  
Default value:
NEWTON 

List of valid keywords:

EPS_ITER {Real} 

Target accuracy for the eigenvalue selfconsistency. If the G0W0 HOMOLUMO gap differs by less than the target accuracy during the iteration, the eigenvalue selfconsistency cycle stops. Unit: Hartree.  
This keyword cannot be repeated and it expects precisely one real.  
Default value:
1.36000000E003 

Default unit:
[eV]

EV_GW_ITER {Integer} 

Maximum number of iterations for eigenvalue selfconsistency cycle. The computational effort of GW scales linearly with this number.  
This keyword cannot be repeated and it expects precisely one integer.  
Default value:
1 
FERMI_LEVEL_OFFSET {Real} 

Fermi level for occ. orbitals: e_HOMO + FERMI_LEVEL_OFFSET; Fermi level for virt. orbitals: e_LUMO  FERMI_LEVEL_OFFSET. In case e_homo + FERMI_LEVEL_OFFSET < e_lumo  FERMI_LEVEL_OFFSET, we set Fermi level = (e_HOMO+e_LUMO)/2. For cubicscaling GW, the Fermi level is always equal to (e_HOMO+e_LUMO)/2 regardless of FERMI_LEVEL_OFFSET.  
This keyword cannot be repeated and it expects precisely one real.  
Default value:
2.00000000E002 
GAMMA_ONLY_SIGMA {Logical} 

If true, the correlation selfenergy is only computed at the Gamma point. The Gamma point itself is obtained by averaging over all kpoints of the DFT mesh.  
This keyword cannot be repeated and it expects precisely one logical.  
The lone keyword behaves as a switch to
.TRUE. 

Default value:
.FALSE. 

Alias names for this keyword: GAMMA 
IC_CORR_LIST {Real} ... or a range {Real}..{Real} 

List of image charge correction from a previous calculation to be applied in G0W0 or evGW. Keyword is active, if the first entry is positive (since IC corrections are positive occupied MOs. The start corresponds to the first corrected GW level.  
This keyword cannot be repeated and it expects a list of reals.  
Default value:
2.72113839E+001 

Default unit:
[eV]

IC_CORR_LIST_BETA {Real} ... or a range {Real}..{Real} 

IC_CORR_LIST for beta spins in case of open shell calculation.  
This keyword cannot be repeated and it expects a list of reals.  
Default value:
2.72113839E+001 

Default unit:
[eV]

IMAGE_CHARGE_MODEL {Logical} 

If true, an image charge model is applied to mimic the renormalization of electronic levels of a molecule at a metallic surface. For this calculation, the molecule has to be reflected on the desired xy image plane. The coordinates of the reflected molecule have to be added to the coord file as ghost atoms. For the ghost atoms, identical basis sets the normal atoms have to be used.  
This keyword cannot be repeated and it expects precisely one logical.  
The lone keyword behaves as a switch to
.TRUE. 

Default value:
.FALSE. 

Alias names for this keyword: IC 
NPARAM_PADE {Integer} 

Number of parameters for the Pade approximation when using the latter for the analytic continuation of the self energy. 16 parameters (corresponding to 8 poles) are are recommended.  
This keyword cannot be repeated and it expects precisely one integer.  
Default value:
16 
NUMB_POLES {Integer} 

Number of poles for the fitting. Usually, two poles are sufficient.  
This keyword cannot be repeated and it expects precisely one integer.  
Default value:
2 
OMEGA_MAX_FIT {Real} 

Determines fitting range for the selfenergy on the imaginary axis: [0, OMEGA_MAX_FIT] for virt orbitals, [OMEGA_MAX_FIT,0] for occ orbitals. Unit: Hartree. Default: 0.734996 H = 20 eV.  
This keyword cannot be repeated and it expects precisely one real.  
Default value:
7.34996000E001 
PERIODIC {Logical} 

If true, the periodic correction scheme is used employing kpoints.  
This keyword cannot be repeated and it expects precisely one logical.  
The lone keyword behaves as a switch to
.TRUE. 

Default value:
.FALSE. 
PRINT_EXX {Keyword} 

Print exchange selfenergy minus exchange correlation potential for Gammaonly calculation (PRINT). For a GW calculation with kpoints we use this output as exchange selfenergy (READ). This is a temporary solution because the hybrid MPI/OMP parallelization in the HFX by Manuel Guidon conflicts with the parallelization in lowscaling GW kpoints which is most efficient with maximum number of MPI tasks and minimum number of OMP threads. For HFX by M. Guidon, the density matrix is fully replicated on every MPI rank which necessitates a high number of OMP threads per MPI rank for large systems to prevent out of memory. Such a high number of OMP threads would slow down the GW calculation severely. Therefore, it was decided to temporarily divide the GW kpoint calculation in a Gammaonly HF calculation with high number of OMP threads to prevent out of memory and a GW kpoint calculation with 1 OMP thread per MPI rank reading the previousHF output.  
This keyword cannot be repeated and it expects precisely one keyword.  
Default value:
FALSE 

List of valid keywords:

RI_SIGMA_X {Logical} 

If true, the exchange selfenergy is calculated approximatively with RI. This is only recommended in case exact exchange is very costly, e.g. when using diffuse basis functions (seems not to work for periodic systems).  
This keyword cannot be repeated and it expects precisely one logical.  
The lone keyword behaves as a switch to
.TRUE. 

Default value:
.TRUE. 
SC_GW0_ITER {Integer} 

Maximum number of iterations for GW0 selfconsistency cycle. The computational effort of GW is not much affected by the number of scGW0 cycles.  
This keyword cannot be repeated and it expects precisely one integer.  
Default value:
1 
UPDATE_XC_ENERGY {Logical} 

If true, the HartreeFock and RPA total energy are printed and the total energy is corrected using exact exchange and the RPA correlation energy.  
This keyword cannot be repeated and it expects precisely one logical.  
The lone keyword behaves as a switch to
.TRUE. 

Default value:
.FALSE. 
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